Wind indicating aeronautical searchlight beacon



Feb. 6, 1934. BOYLE 1,946,351

WIND INDICATING AERONAUTICAL SEARCHLIGHT BEACON Filed July 18, 1929Patented Feb. 6, 1934 UNITED STTES rsr .0 rice WIND INDICATINGAERONAUTICAL SEARCHLIGHT BEACON 5 Claims.

This invention relates to aeronautical searchlight beacons of thatgeneral type spaced from ten to twenty-five miles apart to designatenight airways, and has for an object to provide a beacon of this typewhich will indicate to a night pilot, as soon as he arrives within rangeof the beacon, the exact direction toward which the wind is blowing atthe beacon so that he may have this necessary information available allalong his route in the event of a forced landing.

In the absence of confusing lights, aeronautical search-light beaconsare visible on a clear night at distances of from seventeen totwenty-five miles or more, according to the altitude of the airplane andthe angle of elevation of the beam, 2 elevation of the beam above thehorizontal being generally used to give greatest distance or visibilityto a low cruising pilot. The white search-light beam of the beacon maybe seen to sweep obliquely upward around the horizon during about a ninesecond period alternating with a flash of about one second durationvisible as the lens faces directly toward the airplane.

The present invention contemplated, modifying by coloring or otherwisethis search-light beam periodically as it sweeps around the horizon, sothat a modified ray or flash will appear at about ten second intervals.This modified ray or flash is preferably projected in the directiontoward which the wind is blowing at the beacon and furnishes, at a greatdistance from the beacon, a visible indication of wind direction. Thepilot may fly in the direction of the flash to effect a landing into thewind in the event of a forced landing between beacons, and dispensewiththe usual drifting flare to determine his wind direction.

The invention is illustrated in the accompanying drawing in which-Figure l is a side elevation of the device;

Figure 2 is a fragmentary front elevation of the color screen.

Referring now to the drawing in which like characters of referencedesignate similar parts in the various views, a revolving aeronauticalstarch-light beacon is shown of the usual type installed on highbuildings, water towers, or spe cial' steel towers to guide pilots onnight airways. The beacon comprises a drum casing which surrounds areflector and a source of light comprising a running lamp and a sparelamp which is automatically lighted upon failure of the running lamp inthe usual manner. The drum casing is provided with a lens 2 which isequipped with a set of louver for eliminating stray light.

The drum casing is revolved by a yoke 3 and is clamped in tilted orelevated position by set screws 4 to direct the light beam, indicated at5, obliquely upward at any desired angle, 2 above the horizontal usuallybeing suflicient to clear surrounding trees and buildings and givegreatest distance of visibility to the night pilot. A cylindrical base 6incloses slip rings and brush rigging which carry the projectingcurrent, as well as an electric motor and gearing which rotates the yoke3 in its bearing '7 on a vertical axis of rotation which passes throughthe drum casing l. The drum usually revolves in an azimuth of 360 atabout six revolutions per minute.

In the preferred embodiment of the invention I employ a standard 3 whichis equipped at the bottom with a flange base 9, which may be bolted orotherwise securely fastened near the base of the beacon. A horizontalarm 10 extends from the top of the standard towards the beacon and isspaced considerably above the beacon so as not to interfere with theproper operation of the latter. The armterminates in a bearing 11 inwhich is journaled a vertical shaft 12, which is bolted at the upperend, as shown at 13, or otherwise fixed to, and serves as a pivot for awind vane 14, which swings around freely above the arm 10 under impulseof the wind. Care must be taken to locate the bearing 11 in alinementwith the self-contained vertical axis of rotation of the drum casingheretofore mentioned when mounting the standard.

The pivot shaft 12 carries at its lower end a horizontal rod 15 whichextends parallel with and rearwardly along the vane 14 below the arm 10.The rod 15 is adjustably secured to the pivot shaft 12 by means of ahorizontal eye 16 on the shaft and a set screw 17, and moves as a unitwith the shaft.

Suspended from the free end of the rod is a color screen. 18, preferablyformed of transparent tinted material, such as for instance, green orother colored glass. The screen is mounted in a yoke 19 and may beclamped in various tilted positions parallel with the lens 2 of thebeacon by set screws 20. The stem 21 of the yoke is adjustablevertically on the rod 15 to permit of the screen being placed tocompletely mask the lenses 2 by means of a vertical eye 22 on the rodand a set screw 23. The pivot shaft 12 is in alinement with the verticalaxis of rotation of the beacon, so that when the wind vane swings, thecolor screen is moved in a curved path concentric with the axis ofrotation of the beacon and is properly spaced laterally from the beaconto intercept and color the search-light beam each time the revolvingbeacon registers with the screen.

The color screen is disposed in a plane intersecting the plane of thewind vane at a right angle, that is, it is disposed with its axis oflight projection in the plane of the wind vane so that the screen ismaintained by the vane transversely across the wind. The screen is alsospaced rearwardly from the vertical pivot shaft of the vane and disposednear the tail of the wind vane so that it will be maintained by the vanein leeward of the beacon. Thus the screen is maintained by the vane atall times transversely across the wind in leeward of the beacon so thatit intercepts and colors the search-light beam in the direction towardwhich the wind blows at the beacon. Also, in this leeward position ofthe screen, the beacon serves as a wind break for the screen, spaced ata few inches distant from the screen at all times, which feature is mostimportant where high prevailing winds would tend to shear off the pivotof the screen due to vibration. Due to the beacon being showndiagrammatically in the drawing, this wind break feature may not be atonce apparent, but it will be here pointed out that in practice airwaybeacons of 24 diameter lens have a drum or casing of about 22 inthickness from the lens to the back of the drum, thus the search-lightdrum is just about the same in thickness as in length and in breadth.Hence a 24" screen for example, will be shielded from wind regardless ofwhether the lens, the side, or the back of the beacon drum faces thescreen.

If desired, the screen may be disposed to windward of the beacon byloosening the set screw 17, inserting the rod 15 in the eye 16 from theopposite direction to that shown in the drawing, then tightening the setscrew. In this arrangement the screen will counter-balance the vane andthis will be advantageous in locations where extreme delicacy ofconstruction is necessary to permit the vane to respond to lightbreezes.

The color screen may be formed of any desired material and may be givenany desired color or combination of colors, or may be constructed in anymanner to modify the beam, so long as there is imparted to the beaconsearch-light beam a noticeably different characteristic at some point inits sweep to indicate wind direction at the beacon.

In operation the wind vane 14 maintains the color screen 18 at all timestransversely across the wind in leeward of the beacon. Consequently thescreen intercepts and colors the searchlight beam, in the directiontoward which the wind blows, once during each revolution of the beacon.The resultant colored light ray or flash projected from the beaconobliquely upward will be visible once every ten seconds, and endure forabout one second, according to the timing of the beacon. By noting thecompass direction of the colored wind indicating rays or flashes as hepasses over successive beacons, the pilot will have his wind directioninformation available all along his route in the event of a forcedlanding.

An effect of the color screen, which is most noticeable when flying overthe beacon, is the dimming of the light beam in its down-wind position.This is due to the absorption of light at the instant that the beam ispassing through the screen. The Wind direction indication thus affordedis available at close range, whereas coloring of the flash is the bestlong range indication.

Having thus described my invention what I claim is- 1. As an article ofmanufacture, a wind operated color screen embodying a standard, a windvane, a pivot shaft for the wind vane carried by the standard, a memberextending from the pivot shaft and movable as a unit with the shaft andthe vane, a color screen carried by said member and movable by the vanein a curved 1 path concentric with the pivot shaft, means for clampingthe color screen in tilted position with respect to said shaft, andmeans for securing the color screen in adjusted positions near to orremote from said shaft.

2. In a wind direction indicating beacon, the combination with arevoluble search light having a light source, a drum casing surroundingthe light source and projecting a beam away from the axis of rotation ofthe search light, and a rotatable yoke supporting the drum casing on avertical axis of rotation passing through the drum casing, of a standarddisposed laterally of the axis of rotation of the search light, abearing rigidly supported by the standard in superposed positionrelative to the drum casing and in vertical alinement with said axis ofrotation, a wind vane, a pivot shaft for the vane journaled in thebearing, and a screen operatively connected with the shaft andmaintained by the vane laterally of the drum casing to intercept theprojected beam at a point in its sweep.

3. In a wind direction indicating beacon, the combination with arevoluble search light having a light source, a drum casing surroundingthe light source and projecting a beam away from the axis of rotation ofthe search light, and a rotatable yoke supporting the drum casing on avertical axis of rotation passing through the drum casing, of a standarddisposed laterally of the axis of rotation of the searth light, asupporting bearing on the standard superposed relative to the drumcasing and in vertical alinement with said axis of rotation, a windvane, a pivot shaft for the vane journaled in the bearing and connectedto the vane at a point near one end thereof so that major and minorareas of the vane are disposed on opposite sides of the pivot shaft, atransverse rod carried by the shaft, a screen disposed laterally of thedrum casing, and means operatively connecting the screen to the rod onthe same side of the pivot shaft as the major area of the vane so thatthe screen is maintained by the vane to leeward of the drum casing tointercept the projected beam at a down wind point in its sweep.

4. In a wind direction indicating beacon, the combination with arevoluble search light having a light source, a drum casing surroundingthe light source and projecting a beam away from the axis of rotation ofthe search light and a rotatable yoke supporting the drum casing on avertical axis of rotation passing through the drum casing, of a standarddisposed laterally of the drum casing, a supporting bearing on thestandard superposed relative to the drum casing and in verticalalinement with said axis of rotation, a screen, a wind vane, meansoperatively connecting the screen and vane together to move as a unit,said means rotatably supporting the screen on said bearing to move in apath around the drum casing and intercept the projected beam at a pointin its sweep and. including means for adjusting the screen laterally tospace the screen a minimum distance from the drum casing.

5. In a wind direction indicating beacon, the combination with arevoluble search light having a light source, a drum casing surroundingthe light source and projecting a beam away from the axis of rotation ofthe search light, a rotatable yoke supporting the drum casing upon avertical axis of rotation passing through the drum casing, and a pivotalconnection between the drum casing and the yoke upon which the drumcasing may be tilted on said yoke to project the beam from the lightsource at an angle above the horizontal, of as standard disposedlaterally of the drum casing, a supporting bearing on the standardsuperposed relative to the drum casing and in vertical alinement withsaid axis of rotation, a wind vane, a screen, means operativelyconnecting the screen and vane together to move as a unit, said meansrotatably supporting the screen on said bearing to be moved by the vanein a circular path around the drum casing to intercept the projectedbeam at a point in its sweep and including operative connections adaptedto hold the screen tilted to correspond to the angle of tilt of the drumcasing and means for adjusting the screen vertically to raise the screeninto the tilted beam.

FRANCIS BOYLE.

